Keep Pedaling
(888) 880-3811

Shimano UN55 Bottom Bracket

Item #: BB257F01
USD$19.99 20% off USD$24.99 msrp
Found a Lower Price?
Availability Please make a selection
Quantity
close

Tell a friend! We'll send your friends the page and your message.
Note: You and your friend's email addresses are only used once as a referral. We will not collect or store the email addresses.

Friend's Name:
Your Name:
Friend's Email:
Your Email:
Message
(500 char. max)
Notify Me
Receive an email when this product becomes available.

Enter your name and email to be notified when this product is in stock and available to purchase.
First Name:
Last Name:
Email:

Shimano UN55 Bottom Bracket

High quality Shimano sealed bottom bracket (square taper). Extra strong Aluminum (not plastic) non drive cup. Please choose width and spindle length.

  • English Threaded
Related Products
Hope Ceramic Bottom Bracket Keep your HollowTech II ...
TruVativ Square LE bottom bracket Features and Information ...
Wrench it yourself with Jenson USA Tools! From ...

REVIEW SNAPSHOT®

by PowerReviews
Shimano UN55 Bottom Bracket
 
4.6

(based on 34 reviews)

Ratings Distribution

  • 5 Stars

     

    (23)

  • 4 Stars

     

    (9)

  • 3 Stars

     

    (2)

  • 2 Stars

     

    (0)

  • 1 Stars

     

    (0)

97%

of respondents would recommend this to a friend.

Pros

  • Easy to install (26)
  • Durable (16)
  • Enhances pedaling efficiency (13)
  • Lightweight (5)

Cons

    Best Uses

    • Mountain biking (15)
    • Road biking (15)
      • Reviewer Profile:
      • Avid cyclist (15), Casual/ recreational (7), Commuter (6)
      • Was this a gift?:
      • No (28)

    Most Liked Positive Review

     

    5 star rating

    Bought this BB and so far it is a winner. Very smooth and more importantly, very strong. I put a lot of downward force on my pedals and this BB is stiff and...Read complete review

    Bought this BB and so far it is a winner. Very smooth and more importantly, very strong. I put a lot of downward force on my pedals and this BB is stiff and strong. All my power goes to the wheels.

    VS

    Most Liked Negative Review

     

    Minor problem: loose cap

    I've bought 3 of these UN55 units, and on two of them the aluminum cap appears to be loose on the cartridge, by about .020". I made a plastic spacer to...Read complete review

    I've bought 3 of these UN55 units, and on two of them the aluminum cap appears to be loose on the cartridge, by about .020". I made a plastic spacer to take up the play. On the third unit, the cap seems to fit neatly. Possibly these were packed with the wrong cap?

    Reviewed by 34 customers

    Sort by

    Displaying reviews 1-10

    Back to top

    Previous | Next »

     
    5.0

    GREAT Bottom Bracket

    By Dr Tim

    from Northeast, TX

    About Me Avid Cyclist

    Verified Buyer

    Pros

    • Durable
    • Enhances Pedaling Efficiency

    Cons

      Best Uses

      • Mountain Biking
      • Road Biking

      Comments about Shimano UN55 Bottom Bracket:

      This is a great bottom bracket. I have ordered two of these now. The first one I put on my Mountain Bike. It now has over 1000 miles without any problems at all. The second one, I put on a bike that I am restoring.

      • Was this a gift?:
      • No
       
      5.0

      Great Replacement Bottom Bracket

      By Dr. Tim

      from North East, TX

      About Me Avid Cyclist

      Pros

      • Durable
      • Easy To Install
      • Enhances Pedaling Efficiency

      Cons

        Best Uses

        • Mountain Biking
        • Road Biking

        Comments about Shimano UN55 Bottom Bracket:

        The Shimano UN55 Bottom Bracket is an excellent replacement bottom bracket. I have uses the UN55 on several bikes that I've upgraded and restored. One of them I ride regularly and have over 800 miles on the UN55. I highly recommend this bottom bracket.

        • Was this a gift?:
        • No
         
        5.0

        Great upgrade for 1999 Trek 6500 MTB

        By ek

        from Ahia

        About Me Commuter

        Verified Buyer

        Pros

        • Aluminum Cup
        • Easy To Install
        • Enhances Pedaling Efficiency

        Cons

          Best Uses

          • Mountain Biking

          Comments about Shimano UN55 Bottom Bracket:

          With my limited bike knowledge, took some time scratching around to determine the UN55 was correct replacement.

          • Was this a gift?:
          • No
           
          4.0

          Solid part, very smooth!

          By Frazinator

          from Guelph Ontario

          About Me Avid Cyclist

          Verified Reviewer

          Pros

          • Easy To Install
          • Enhances Pedaling Efficiency

          Cons

            Best Uses

            • Road Biking

            Comments about Shimano UN55 Bottom Bracket:

            This is an awesome bottom bracket for fixed gear bicycles, I bought it to go with a pure-fix crank and they work well together (ie. Square taper). The only thing I would say negative about it, which applies mainly to track/fixed bikes. I had a friend who's chain snapped and in that process (including a bail) the bottom bracket bent a tiny amount, but was barely enough to notice while riding.

            • Was this a gift?:
            • No
             
            4.0

            Good product at good price

            By markw

            from Charleston, SC

            About Me Avid Cyclist

            Verified Buyer

            Pros

            • Easy To Install
            • Enhances Pedaling Efficiency

            Cons

              Best Uses

                Comments about Shimano UN55 Bottom Bracket:

                Bottom bracket on road bike finally wore out, this was easy to install and greatly improved peddling.

                • Was this a gift?:
                • No
                 
                4.0

                Execellent Easy to Install

                By Dean

                from Moberly, MO

                About Me Casual/ Recreational

                Verified Buyer

                Pros

                • Easy To Install

                Cons

                  Best Uses

                    Comments about Shimano UN55 Bottom Bracket:

                    I used this to replace the cheap factory FSA that was a heavy steal consturciton, yet quickly (under 500 miles) developed a grating sound while cranking hard up hills. Though I am a heavier rider at 210lbs and am riding a low end bike that's just one step up from buying one off the shelf at Walmart. Installation was easy, only had to do a minor adjustment on the high and low stops of the front derailer as the offset was slightly different on the drivetrain side from the FSA bracket. Pedalling feels smoother after around 200 miles on the new bottom bracket than it ever did on this bike before. Happy so far with this product.

                    • Was this a gift?:
                    • No

                    (1 of 1 customers found this review helpful)

                     
                    4.0

                    Good fix to worn cup and spindle bb

                    By Gr1m

                    from Cape Cod ,MA

                    About Me Avid Cyclist

                    Verified Buyer

                    Pros

                    • Easy To Install
                    • Enhances Pedaling Efficiency

                    Cons

                      Best Uses

                      • Road Biking

                      Comments about Shimano UN55 Bottom Bracket:

                      I've used this bottom bracket a couple times to replace pitted and rusted spindles. Very easy installation and reliable. Although, I do like my RaceFace external bearing bb a little better.

                      • Was this a gift?:
                      • No

                      (1 of 1 customers found this review helpful)

                       
                      5.0

                      Easy to replace bottom bracket

                      By Gregg

                      from Olathe, KS

                      About Me Commuter

                      Verified Reviewer

                      Pros

                      • Easy To Install
                      • Enhances Pedaling Efficiency

                      Cons

                        Best Uses

                        • Road Biking

                        Comments about Shimano UN55 Bottom Bracket:

                        I was glad to be able to replace the bottom bracket on my own. Easy instructions.

                        • Was this a gift?:
                        • No

                        (1 of 1 customers found this review helpful)

                         
                        5.0

                        So good, I had to buy another one.

                        By Skidmark

                        from Kingman, Az.

                        About Me Casual/ Recreational

                        Verified Reviewer

                        Pros

                        • Durable
                        • Easy To Install
                        • Enhances Pedaling Efficiency

                        Cons

                        • None

                        Best Uses

                        • Mountain Biking

                        Comments about Shimano UN55 Bottom Bracket:

                        I had bought one of these for my road bike, and had such good luck with it, when my Kona Lanai started clunking, I got one for it. I didn't realize how bad my bottom bracket was, until I changed it. Wow, what a difference it made, the bike rides so much better now.

                        • Was this a gift?:
                        • No
                         
                        5.0

                        Good replacement Bottom Bracket

                        By Skidmark

                        from Kingman, Az.

                        About Me Casual/ Recreational

                        Verified Reviewer

                        Pros

                        • Durable
                        • Easy To Install
                        • Enhances Pedaling Efficiency

                        Cons

                        • None

                        Best Uses

                        • Road Biking

                        Comments about Shimano UN55 Bottom Bracket:

                        I bought this for my cheapy road bike, when the factory BB started getting loose. It was easy to install, and is very smooth and solid. It made a huge difference in how my bike rides now.

                        • Was this a gift?:
                        • No

                        Displaying reviews 1-10

                        Back to top

                        Previous | Next »

                        Jenson USA ships worldwide, including APO/FPO addresses. For a quote, simply add the items you are interested in to your shopping cart and look for the "Shipping Options" box. You don't have to login or create an account to see shipping charges.

                        Some manufacturers restrict where we can ship their products. If this item has shipping restrictions, they are listed below. If you'd like to buy an item that we cannot ship to your preferred address, we can accept your foreign credit card and ship to a USA address for you.

                        Get free shipping with your $50 purchase today when you choose Standard Shipping at checkout. Please note this offer is only available to physical shipping addresses in the 48 continental United States (no PO Boxes), and oversize charges still apply on some heavy/large items

                        Email Specials

                        Sign up for our weekly specials delivered via email

                         

                        Free Shipping Offer

                        Get free Standard Shipping with your $50 purchase today! Just choose Standard Shipping during checkout.

                        Please note this offer is only available to physical shipping addresses in the 48 continental United States (no PO Boxes), and oversize charges still apply on some heavy/large items.